Presser-foot mechanism.



E. E. WINKLEY.

' IBLBSSIIB- FOOT MECHANISM.

APPLICATION mum JAH.14, 1905.

980,726. a PatentedJa.1 1.3,1911.

T FGFFIGE.

EREtSTUS E. VJK"\ .'LEY, C LYNN, 'MASSACHUSETTS.

P ESSER-FOOT MECHANISM.

scones.

Specification of Letters .Eatent.

ratented Jan. 3, 1911.

Application file.-

14, 1905. Serial No. 240,924.

To all whom it may concern:

Be itknown that I, ERASTCS E. Wrxnnnr,

a. citizen of the United States residin at lowing to be a full, clear, and exact descrip' tion of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to presser foot mechanism for shoe sewing machines and particularly to presser foot mechanism for sole sewing machines of the lock stitch type, which are commonly used to unite the welt and outsole of a welted shoe.

The present invention is intended primarily as an improvement on the presser foot mechanism disclosed in the patent to Z. T. French and VJ. C. Meyer, No. 473.870, dated April 26, 1892. Certain features of the in vention. are, however, applicable to other forms of presser foot mechanism as will hereinafter appear. 7

In the presser toot mechanism disclosed in the patent to French and Meyer above referred to the presser foot is moved to clamp the work by means of cam-actuated mechanism, which, in order to allow the presser foot to accommodate itself to variations in the thickness of stock, is disconnected from the prcsser foot at certain times during the operation of the machine, the presser foot at these times being held lightly against the work by spring pressure. The mechanism for actuating the presser foot comprises a camactuated lever provided with a pawl which engages a. ratchet connected with the prcsser tootl The pawl is moved out (if-engagement with the ratchet in'order to allow the presser foot to move independently of its actuating .mechanism in accommodating itself to stock of different thickness. During such movement of the presser foot the ratchet moves with relation to the pawl, so that when the pawl again engages the ratchet there is more or less lost motion and the movement imparted to the ratchet by the pawl conse uentiy varies. To

- obviate the efiect of this 0st motion on the presser foot, 3. yielding connection is provided between the ratchet and the presser foot so that a longer throw can he imparted to the pawl than would otherwise be possible, and thereby a-sufiicient pressure put upon the presser foot through the'yielding connection to clamp thework notwithstanding the lost motion between the pawl and ratchet. The provision of a yielding con nection between the ratchet and the presser foot however necessitates the provision of a separate locking device for locking the presser foot against. back pressure exerted thereon during the puncturing movement of the awl and the formation and setting of the stitch. This locking device consists .of' a pawl which is moved into and out of engagement with a ratchet mounted to move with the presser foot. This ratchet assumes different positions with relation to the locking pawl the stock varies in thickness, so that there is more or less lost motion between the pawl and ratchet and the presser foot is not always held rigidly in position but is allowed to yield during the sewing operation so that a loose seam results.

The principal object of the present invention is to provide 'a presser foot mechanism by which the presser foot is actuated to exert a uniform clamping pressure on the work to press the layers of the work together regardless of variations in the thickness of the stock, and by. which the presser foot is securely locked in clamping position.

A further objectof the invention is to provide a presser foot mechanism comprising a comparatively small number of parts arranged in a simple and compact manner and having an improved mode. of operation, and in general to improve the construction, arrangement and mode of operation of the various parts of presser. foot mechanisms.

\Vith these objects in view the present invention contemplateswthe provision of a presser foot actuating mechanism constructed and arranged to alternately engage and disengage the presser foot and means for automatically adjusting said mechanism to take u lost moti0n.'.,--

In the illustratedembodiment of the invention hereinafter specifically described the mechanism for actuating the presser foot comprises a cam actuated lever and automatically adjustable connections between the lever and the presser foot. The automatically adjustable connections comprise a pawl arranged to engage a'ratchet mounted to move with the presser foot, and yieldinglyor spring-actuated means for 'between the cam-actuate moved by the cam-actuated lever a certain predetermined distance, the same uniform throw being imparted to the presser foot'regardless of the position which it has assumed in accommodating itself to the stock. As the pawl is locked against backward movement the presser foot exerts a positive pressure upon the work and is held securely a gainst back pressure exerted thereon during the puncturing movement of the awl and the forming and setting of the stitch, no additional locking devices for holding the presser foot in position being necessary.

The mechanism above referred toembodies the present invention in the best form that has yet been devised but it is to be understood that except as defined in the claims the invention isnot limited thereto but that broadly considered it may be embodied in any mechanism for actuating the presser foot which is automatically adjusted to take up lost motion.

it is believed that the pawl and the means above referred to for actuating the aWl to take up lostmotion and for lock ng the pawl against backward movement are neW,.

and i1 is accordingly considered that this pawl and its actuating and locking means constitute a feature of theinvention whether they are utilized asconnections in a mechanism which imparts a positive clau'iping movement to the prcsscr foot or merely as a locking means for preventing backward movcnu-nt of the presser foot after having been forced into contact with the work.

The present invention will be clearly understood from an inspection of the accompanying drawing in which is illustrated a presser foot mechanism embodying the same in its preferred form.

Referring to the drawing. Figure 1 is a view in side elevation of a lock stitch sole sewing machine, provided with a presscr foot'mechanism embodying the preferred form of the present invention, a portion of the frame of the machine being broken away and the cam shaft being shown in section; Fig. 2 is a view in side elevation of the prcsser foot mechanism detached from the n'u chiue the parts being shown in the positions which they assume while the presser foot is accommmlating itselfto variations in the thickness of stock; and Fig. 3 is afplan' view of the mechanism illustrated in Fig. 2.

The macl'inc illustrated in Fig. 1' of the drawing. with the exception of the presser foot mechanism, 'is the same in construction and mode of operation as the machine disenemas closed in the patent to French and Meyer hereinbefore referred to, reference to which is made for a complete disclosure thereof.

The presser foot is indicated at 1 and is secured to the forward end of a lever 2 piv- 7o oted at 3 upon the frame of the machine. To the rear end of the presser foot lever 2 is pivotally connected the frame 4 which forms the means for adjusting the pull-off mechanism as the thickness of the stock beneath the presser foot varies, as fully illustrated and" described in the patent to French and Meyer above referred-to. A light spring 5 secured at one end of the frame of the machine and at the other end bearing against the frame 4 acts to hold the presser foot lightly in contact with the work when released from its actuating mechanism, the presser foot at this time moving toward and from the work support 6 independently of the actuating mechanism to' accommodate itself to variations in the thickness of the stock.

The mechanism for actuating'the presser foot to compress and clamp the work comprises a cam-actuated lever 7 and connections between the lever 7 and the prcsscr foot lever 2. The lever 7 is pivoted at its rear end upon the hub of a lever 11 herein after referred to, and intermediate its ends 9 is provided with an upwardly extending projection 8 in which is jonrnaled a cam roll which engages a cam groove 9 in a cam disk secured to'the cam shaft 10 of the machine.

The connections between the cam actuated 100 dever 7 andthe presser foot lever u consist of a lever 11 pivotallymounted upon a stud 12 secured in the frame of the machine. a spring pressed pawl 13 mounted in the forward end of the lever 11, and a rotatable 1055 cam 14 also mounted upon the lever 11 near its forward end. The cam 14 is arranged to bear upon a roll 15 supported in a bracket 16 secured to the frame of the machine, and is acted upon by a light coiled spring 17 one 110 end of which is attached to the cam and the other end to the lever 7. The lever 7 is provided near its forward end with a downwardly extending project-ion 18 upon which is mounted an arm 19 extending beneath the 115 cam 14 in position. to contact therewith during the upward movement of the lever T. The lever 7 is also provided with a projection 20 which during the downward movement of the lever is arranged to engage a projection on the cam 14 and rotate the cam forward against the force of the spring 17. The upward movement of the lever '1 thus brings the arm 19 into contact with the cam 14 and raises the cam and the lever 11, upon 125 j which the cam and the-pawl 13 are mounted. while the downward movement of the lever 7 by the engagement of the projection 20 with the projection on the cam l t depresses the lever 11 until tho-cam rests on the roll 15 13 scones andthen rotates the coin to allow the lever 11 to be still further depressed. During the last portion of the downward movement of the lever 11 a projection on the pawl 13 is brou ht into contact with a fixed pin 21 and therdby the pawl is moved out of engage ment with a ratchet 22 upon the rear end of the presser foot lever. The presser foot is thus disconnected from its actuating mechanism and is free to move with relation thereto so as to accommodate variations in the thickness of the stock, the presser foot at this time being pressed lightly against the work by the spring 5. During the first portion of the upward movement of the lever 7 the cam 14 is allowed to rotate under the force of the spring 17 the cam being rotated by the spring until the lever .11'is raised a sufficient distance to bring the pawl 13 into engagement with the ratchet and seat it firmly against one of the ratchet teeth.

The extent of the upward movement imparted to the lever 11 by the 'cam 14 varies with the position of the presser foot lever so that all lost motion between the pawl 13 and the ratchet 22 is taken up before the arm 19 is bIQught into contact with the cam. It will be seen that the arm 19 engages the cam 14 at a certain predetermined point in the movement of the lever 7 so that the presser foot is always moved positively a uniform distance from any position which it assumes on account of variations in the thickness of the stock and the layers of the work are firmly pressed together. that-the shape and arrangement of the cam 14: is such that the pawl is loclged against backward movement so that the presser foot is positively held in the position to which it is moved by its actuating mechanism. In order to vary the extent of the movement imparted to the presser foot to compress and clamp the work, the arm 19 is pivotally mounted upon the projection 18 of the lever 7 and is provided with a rearward projection which is engaged by ax: adjustable stop cam 23 mounted upon the lever. The spring 17 acts .to a greater or less extent, depending on the strength of the spring, to force the presser 'foot toward the work with a yielding pressure after the pawl 13 is seated against a tooth of the ratchet 22. It will be obvious that this movement of the V presser foot may be relied upon to bring It will also be seensupport the machine illustrated in Fig. 1 is provided with two hand levers'2 l and 25, the lever 2 being rigidly secured to thepre-sser foot'lcver and the lever 25 beingv pivotaily mounted concentrically with the presser foot lever and connected by a link ,2 6- with the pawl 13. One end of the linlikQfi. is pivctally connected to the lower end of the lever 25 and the other end of the' l'ink is provided with a, fork which engages apin projecting laterally from the pawl 13. The levers 24 and 25 are arranged so as to be conveniently grasped by the operator, a movement of the lever 25 toward the lever 2-1 serving to disengage the pawl 13 from the ratchet 22 so as to allow the presser foot. to be raised by means of the lever 24.

The operation of the illustrated embodiment of the invention has been indicated in the description given above of the construc- 8 tion and arrangement of the various parts and will be readily understood by those skilled in the art. i

The nature and scope of the invention having been indicated and a preferred form of the invention having been specifically described, what is claimed is 1. A sole sewing machine, having, in combination, a .presser foot, mechanism for ac-- tuating the presser foot to clamp the work arranged to alternately engageand disen-' gage the presser foot, and means for automatically adjusting said mechanism after; engagement with the presser foot to take up lost motion and cause the presser foot to ex-' 100 ert the-same predetermined clamping action on the work regardless of its thickness, substantially as described. I

2. A sole sewing machine, having, in combination, a presser foot, mechanism for ac- 195 tuating the prcsser foot, comprising a pawl, means for moving the pawl varying distances 'to cause it to engage the presser foot in any position which it assumes in ac'com' modating itself to stock of varying thick-' 113 ness and for thereafter positively moving the pawl uniform distances toactuate the presser foot to clamp the Work, substantially as described.

3. A sole sewing machine, having, in comratchet, and means for actuating the pawl to take uplost motion while in engagement with the ratchet and for locking the pawl against backward movement, substantially as described.

A sole sewing machine, having, in co: A25 bination, a presser foot, a cam actuated actuating lever therefor, connections between said lever and presser foot, means for actuating said connections to release the resser foot and allow it to accommodate itse ftostock of 130 varying thickness, and means for actuating l gagement with the ratchet to take up lost said. connections to engage the presser foot I motion and for locking the pawl against and for moving said connections with relabackward movement, and means for moving tion to the lever to take up lost motion bethe pawl into and out of engagement with tween the presser foot and its actuating lethe ratchet, substantially as described. ver, substantially as described. In testimony whereof I gfi'ix my signab A sole sewing machine, having, in COIlll ture, in presence of two witnesses.

ination, a presser foot, a cam actuated ac- 1 T tuating lever therefor, a ratchet mounted ERASTUS VVHMKLEL to move with the presser foot, a pawl actn- Witnesses: ated by the lever, means for moving the GRACE C. MOONEY, pawl independently of the lever when in en- FARNUM F. Donsny'. 

